[PATCH] inode_diet: Replace inode.u.generic_ip with inode.i_private
[pandora-kernel.git] / fs / ocfs2 / dlmglue.c
index 7532f80..8801e41 100644 (file)
@@ -67,19 +67,13 @@ struct ocfs2_mask_waiter {
        unsigned long           mw_goal;
 };
 
-static void ocfs2_inode_bast_func(void *opaque,
-                                 int level);
-static void ocfs2_dentry_bast_func(void *opaque,
-                                 int level);
-static void ocfs2_super_bast_func(void *opaque,
-                                 int level);
-static void ocfs2_rename_bast_func(void *opaque,
-                                  int level);
+static struct ocfs2_super *ocfs2_get_dentry_osb(struct ocfs2_lock_res *lockres);
+static struct ocfs2_super *ocfs2_get_inode_osb(struct ocfs2_lock_res *lockres);
 
 /*
- * Return value from ocfs2_convert_worker_t functions.
+ * Return value from ->downconvert_worker functions.
  *
- * These control the precise actions of ocfs2_generic_unblock_lock()
+ * These control the precise actions of ocfs2_unblock_lock()
  * and ocfs2_process_blocked_lock()
  *
  */
@@ -96,16 +90,15 @@ struct ocfs2_unblock_ctl {
        enum ocfs2_unblock_action unblock_action;
 };
 
-static int ocfs2_unblock_meta(struct ocfs2_lock_res *lockres,
-                             struct ocfs2_unblock_ctl *ctl);
-static int ocfs2_unblock_data(struct ocfs2_lock_res *lockres,
-                             struct ocfs2_unblock_ctl *ctl);
-static int ocfs2_unblock_inode_lock(struct ocfs2_lock_res *lockres,
-                                   struct ocfs2_unblock_ctl *ctl);
-static int ocfs2_unblock_dentry_lock(struct ocfs2_lock_res *lockres,
-                                    struct ocfs2_unblock_ctl *ctl);
-static int ocfs2_unblock_osb_lock(struct ocfs2_lock_res *lockres,
-                                 struct ocfs2_unblock_ctl *ctl);
+static int ocfs2_check_meta_downconvert(struct ocfs2_lock_res *lockres,
+                                       int new_level);
+static void ocfs2_set_meta_lvb(struct ocfs2_lock_res *lockres);
+
+static int ocfs2_data_convert_worker(struct ocfs2_lock_res *lockres,
+                                    int blocking);
+
+static int ocfs2_dentry_convert_worker(struct ocfs2_lock_res *lockres,
+                                      int blocking);
 
 static void ocfs2_dentry_post_unlock(struct ocfs2_super *osb,
                                     struct ocfs2_lock_res *lockres);
@@ -114,12 +107,67 @@ static void ocfs2_dentry_post_unlock(struct ocfs2_super *osb,
  * OCFS2 Lock Resource Operations
  *
  * These fine tune the behavior of the generic dlmglue locking infrastructure.
+ *
+ * The most basic of lock types can point ->l_priv to their respective
+ * struct ocfs2_super and allow the default actions to manage things.
+ *
+ * Right now, each lock type also needs to implement an init function,
+ * and trivial lock/unlock wrappers. ocfs2_simple_drop_lockres()
+ * should be called when the lock is no longer needed (i.e., object
+ * destruction time).
  */
 struct ocfs2_lock_res_ops {
-       void (*bast)(void *, int);
-       int  (*unblock)(struct ocfs2_lock_res *, struct ocfs2_unblock_ctl *);
+       /*
+        * Translate an ocfs2_lock_res * into an ocfs2_super *. Define
+        * this callback if ->l_priv is not an ocfs2_super pointer
+        */
+       struct ocfs2_super * (*get_osb)(struct ocfs2_lock_res *);
+
+       /*
+        * Optionally called in the downconvert (or "vote") thread
+        * after a successful downconvert. The lockres will not be
+        * referenced after this callback is called, so it is safe to
+        * free memory, etc.
+        *
+        * The exact semantics of when this is called are controlled
+        * by ->downconvert_worker()
+        */
        void (*post_unlock)(struct ocfs2_super *, struct ocfs2_lock_res *);
 
+       /*
+        * Allow a lock type to add checks to determine whether it is
+        * safe to downconvert a lock. Return 0 to re-queue the
+        * downconvert at a later time, nonzero to continue.
+        *
+        * For most locks, the default checks that there are no
+        * incompatible holders are sufficient.
+        *
+        * Called with the lockres spinlock held.
+        */
+       int (*check_downconvert)(struct ocfs2_lock_res *, int);
+
+       /*
+        * Allows a lock type to populate the lock value block. This
+        * is called on downconvert, and when we drop a lock.
+        *
+        * Locks that want to use this should set LOCK_TYPE_USES_LVB
+        * in the flags field.
+        *
+        * Called with the lockres spinlock held.
+        */
+       void (*set_lvb)(struct ocfs2_lock_res *);
+
+       /*
+        * Called from the downconvert thread when it is determined
+        * that a lock will be downconverted. This is called without
+        * any locks held so the function can do work that might
+        * schedule (syncing out data, etc).
+        *
+        * This should return any one of the ocfs2_unblock_action
+        * values, depending on what it wants the thread to do.
+        */
+       int (*downconvert_worker)(struct ocfs2_lock_res *, int);
+
        /*
         * LOCK_TYPE_* flags which describe the specific requirements
         * of a lock type. Descriptions of each individual flag follow.
@@ -137,46 +185,42 @@ struct ocfs2_lock_res_ops {
  */
 #define LOCK_TYPE_REQUIRES_REFRESH 0x1
 
-typedef int (ocfs2_convert_worker_t)(struct ocfs2_lock_res *, int);
-static int ocfs2_generic_unblock_lock(struct ocfs2_super *osb,
-                                     struct ocfs2_lock_res *lockres,
-                                     struct ocfs2_unblock_ctl *ctl,
-                                     ocfs2_convert_worker_t *worker);
+/*
+ * Indicate that a lock type makes use of the lock value block. The
+ * ->set_lvb lock type callback must be defined.
+ */
+#define LOCK_TYPE_USES_LVB             0x2
 
 static struct ocfs2_lock_res_ops ocfs2_inode_rw_lops = {
-       .bast           = ocfs2_inode_bast_func,
-       .unblock        = ocfs2_unblock_inode_lock,
+       .get_osb        = ocfs2_get_inode_osb,
        .flags          = 0,
 };
 
 static struct ocfs2_lock_res_ops ocfs2_inode_meta_lops = {
-       .bast           = ocfs2_inode_bast_func,
-       .unblock        = ocfs2_unblock_meta,
-       .flags          = LOCK_TYPE_REQUIRES_REFRESH,
+       .get_osb        = ocfs2_get_inode_osb,
+       .check_downconvert = ocfs2_check_meta_downconvert,
+       .set_lvb        = ocfs2_set_meta_lvb,
+       .flags          = LOCK_TYPE_REQUIRES_REFRESH|LOCK_TYPE_USES_LVB,
 };
 
 static struct ocfs2_lock_res_ops ocfs2_inode_data_lops = {
-       .bast           = ocfs2_inode_bast_func,
-       .unblock        = ocfs2_unblock_data,
+       .get_osb        = ocfs2_get_inode_osb,
+       .downconvert_worker = ocfs2_data_convert_worker,
        .flags          = 0,
 };
 
 static struct ocfs2_lock_res_ops ocfs2_super_lops = {
-       .bast           = ocfs2_super_bast_func,
-       .unblock        = ocfs2_unblock_osb_lock,
        .flags          = LOCK_TYPE_REQUIRES_REFRESH,
 };
 
 static struct ocfs2_lock_res_ops ocfs2_rename_lops = {
-       .bast           = ocfs2_rename_bast_func,
-       .unblock        = ocfs2_unblock_osb_lock,
        .flags          = 0,
 };
 
 static struct ocfs2_lock_res_ops ocfs2_dentry_lops = {
-       .bast           = ocfs2_dentry_bast_func,
-       .unblock        = ocfs2_unblock_dentry_lock,
+       .get_osb        = ocfs2_get_dentry_osb,
        .post_unlock    = ocfs2_dentry_post_unlock,
+       .downconvert_worker = ocfs2_dentry_convert_worker,
        .flags          = 0,
 };
 
@@ -187,24 +231,6 @@ static inline int ocfs2_is_inode_lock(struct ocfs2_lock_res *lockres)
                lockres->l_type == OCFS2_LOCK_TYPE_RW;
 }
 
-static inline int ocfs2_is_super_lock(struct ocfs2_lock_res *lockres)
-{
-       return lockres->l_type == OCFS2_LOCK_TYPE_SUPER;
-}
-
-static inline int ocfs2_is_rename_lock(struct ocfs2_lock_res *lockres)
-{
-       return lockres->l_type == OCFS2_LOCK_TYPE_RENAME;
-}
-
-static inline struct ocfs2_super *ocfs2_lock_res_super(struct ocfs2_lock_res *lockres)
-{
-       BUG_ON(!ocfs2_is_super_lock(lockres)
-              && !ocfs2_is_rename_lock(lockres));
-
-       return (struct ocfs2_super *) lockres->l_priv;
-}
-
 static inline struct inode *ocfs2_lock_res_inode(struct ocfs2_lock_res *lockres)
 {
        BUG_ON(!ocfs2_is_inode_lock(lockres));
@@ -219,6 +245,14 @@ static inline struct ocfs2_dentry_lock *ocfs2_lock_res_dl(struct ocfs2_lock_res
        return (struct ocfs2_dentry_lock *)lockres->l_priv;
 }
 
+static inline struct ocfs2_super *ocfs2_get_lockres_osb(struct ocfs2_lock_res *lockres)
+{
+       if (lockres->l_ops->get_osb)
+               return lockres->l_ops->get_osb(lockres);
+
+       return (struct ocfs2_super *)lockres->l_priv;
+}
+
 static int ocfs2_lock_create(struct ocfs2_super *osb,
                             struct ocfs2_lock_res *lockres,
                             int level,
@@ -247,9 +281,6 @@ static int ocfs2_meta_lock_update(struct inode *inode,
                                  struct buffer_head **bh);
 static void ocfs2_drop_osb_locks(struct ocfs2_super *osb);
 static inline int ocfs2_highest_compat_lock_level(int level);
-static inline int ocfs2_can_downconvert_meta_lock(struct inode *inode,
-                                                 struct ocfs2_lock_res *lockres,
-                                                 int new_level);
 
 static void ocfs2_build_lock_name(enum ocfs2_lock_type type,
                                  u64 blkno,
@@ -352,6 +383,13 @@ void ocfs2_inode_lock_res_init(struct ocfs2_lock_res *res,
        ocfs2_lock_res_init_common(OCFS2_SB(inode->i_sb), res, type, ops, inode);
 }
 
+static struct ocfs2_super *ocfs2_get_inode_osb(struct ocfs2_lock_res *lockres)
+{
+       struct inode *inode = ocfs2_lock_res_inode(lockres);
+
+       return OCFS2_SB(inode->i_sb);
+}
+
 static __u64 ocfs2_get_dentry_lock_ino(struct ocfs2_lock_res *lockres)
 {
        __be64 inode_blkno_be;
@@ -362,6 +400,13 @@ static __u64 ocfs2_get_dentry_lock_ino(struct ocfs2_lock_res *lockres)
        return be64_to_cpu(inode_blkno_be);
 }
 
+static struct ocfs2_super *ocfs2_get_dentry_osb(struct ocfs2_lock_res *lockres)
+{
+       struct ocfs2_dentry_lock *dl = lockres->l_priv;
+
+       return OCFS2_SB(dl->dl_inode->i_sb);
+}
+
 void ocfs2_dentry_lock_res_init(struct ocfs2_dentry_lock *dl,
                                u64 parent, struct inode *inode)
 {
@@ -630,17 +675,19 @@ static int ocfs2_generic_handle_bast(struct ocfs2_lock_res *lockres,
        return needs_downconvert;
 }
 
-static void ocfs2_generic_bast_func(struct ocfs2_super *osb,
-                                   struct ocfs2_lock_res *lockres,
-                                   int level)
+static void ocfs2_blocking_ast(void *opaque, int level)
 {
+       struct ocfs2_lock_res *lockres = opaque;
+       struct ocfs2_super *osb = ocfs2_get_lockres_osb(lockres);
        int needs_downconvert;
        unsigned long flags;
 
-       mlog_entry_void();
-
        BUG_ON(level <= LKM_NLMODE);
 
+       mlog(0, "BAST fired for lockres %s, blocking %d, level %d type %s\n",
+            lockres->l_name, level, lockres->l_level,
+            ocfs2_lock_type_string(lockres->l_type));
+
        spin_lock_irqsave(&lockres->l_lock, flags);
        needs_downconvert = ocfs2_generic_handle_bast(lockres, level);
        if (needs_downconvert)
@@ -650,30 +697,6 @@ static void ocfs2_generic_bast_func(struct ocfs2_super *osb,
        wake_up(&lockres->l_event);
 
        ocfs2_kick_vote_thread(osb);
-
-       mlog_exit_void();
-}
-
-static void ocfs2_inode_bast_func(void *opaque, int level)
-{
-       struct ocfs2_lock_res *lockres = opaque;
-       struct inode *inode;
-       struct ocfs2_super *osb;
-
-       mlog_entry_void();
-
-       BUG_ON(!ocfs2_is_inode_lock(lockres));
-
-       inode = ocfs2_lock_res_inode(lockres);
-       osb = OCFS2_SB(inode->i_sb);
-
-       mlog(0, "BAST fired for inode %llu, blocking %d, level %d type %s\n",
-            (unsigned long long)OCFS2_I(inode)->ip_blkno, level,
-            lockres->l_level, ocfs2_lock_type_string(lockres->l_type));
-
-       ocfs2_generic_bast_func(osb, lockres, level);
-
-       mlog_exit_void();
 }
 
 static void ocfs2_locking_ast(void *opaque)
@@ -718,52 +741,6 @@ static void ocfs2_locking_ast(void *opaque)
        spin_unlock_irqrestore(&lockres->l_lock, flags);
 }
 
-static void ocfs2_super_bast_func(void *opaque,
-                                 int level)
-{
-       struct ocfs2_lock_res *lockres = opaque;
-       struct ocfs2_super *osb;
-
-       mlog_entry_void();
-       mlog(0, "Superblock BAST fired\n");
-
-       BUG_ON(!ocfs2_is_super_lock(lockres));
-               osb = ocfs2_lock_res_super(lockres);
-       ocfs2_generic_bast_func(osb, lockres, level);
-
-       mlog_exit_void();
-}
-
-static void ocfs2_rename_bast_func(void *opaque,
-                                  int level)
-{
-       struct ocfs2_lock_res *lockres = opaque;
-       struct ocfs2_super *osb;
-
-       mlog_entry_void();
-
-       mlog(0, "Rename BAST fired\n");
-
-       BUG_ON(!ocfs2_is_rename_lock(lockres));
-
-       osb = ocfs2_lock_res_super(lockres);
-       ocfs2_generic_bast_func(osb, lockres, level);
-
-       mlog_exit_void();
-}
-
-static void ocfs2_dentry_bast_func(void *opaque, int level)
-{
-       struct ocfs2_lock_res *lockres = opaque;
-       struct ocfs2_dentry_lock *dl = lockres->l_priv;
-       struct ocfs2_super *osb = OCFS2_SB(dl->dl_inode->i_sb);
-
-       mlog(0, "Dentry bast: level: %d, name: %s\n", level,
-            lockres->l_name);
-
-       ocfs2_generic_bast_func(osb, lockres, level);
-}
-
 static inline void ocfs2_recover_from_dlm_error(struct ocfs2_lock_res *lockres,
                                                int convert)
 {
@@ -820,7 +797,7 @@ static int ocfs2_lock_create(struct ocfs2_super *osb,
                         OCFS2_LOCK_ID_MAX_LEN - 1,
                         ocfs2_locking_ast,
                         lockres,
-                        lockres->l_ops->bast);
+                        ocfs2_blocking_ast);
        if (status != DLM_NORMAL) {
                ocfs2_log_dlm_error("dlmlock", status, lockres);
                ret = -EINVAL;
@@ -938,6 +915,9 @@ static int ocfs2_cluster_lock(struct ocfs2_super *osb,
 
        ocfs2_init_mask_waiter(&mw);
 
+       if (lockres->l_ops->flags & LOCK_TYPE_USES_LVB)
+               lkm_flags |= LKM_VALBLK;
+
 again:
        wait = 0;
 
@@ -1005,12 +985,12 @@ again:
                status = dlmlock(osb->dlm,
                                 level,
                                 &lockres->l_lksb,
-                                lkm_flags|LKM_CONVERT|LKM_VALBLK,
+                                lkm_flags|LKM_CONVERT,
                                 lockres->l_name,
                                 OCFS2_LOCK_ID_MAX_LEN - 1,
                                 ocfs2_locking_ast,
                                 lockres,
-                                lockres->l_ops->bast);
+                                ocfs2_blocking_ast);
                if (status != DLM_NORMAL) {
                        if ((lkm_flags & LKM_NOQUEUE) &&
                            (status == DLM_NOTQUEUED))
@@ -2072,7 +2052,7 @@ static int ocfs2_dlm_debug_open(struct inode *inode, struct file *file)
                mlog_errno(ret);
                goto out;
        }
-       osb = (struct ocfs2_super *) inode->u.generic_ip;
+       osb = inode->i_private;
        ocfs2_get_dlm_debug(osb->osb_dlm_debug);
        priv->p_dlm_debug = osb->osb_dlm_debug;
        INIT_LIST_HEAD(&priv->p_iter_res.l_debug_list);
@@ -2267,24 +2247,20 @@ complete_unlock:
        mlog_exit_void();
 }
 
-typedef void (ocfs2_pre_drop_cb_t)(struct ocfs2_lock_res *, void *);
-
-struct drop_lock_cb {
-       ocfs2_pre_drop_cb_t     *drop_func;
-       void                    *drop_data;
-};
-
 static int ocfs2_drop_lock(struct ocfs2_super *osb,
-                          struct ocfs2_lock_res *lockres,
-                          struct drop_lock_cb *dcb)
+                          struct ocfs2_lock_res *lockres)
 {
        enum dlm_status status;
        unsigned long flags;
+       int lkm_flags = 0;
 
        /* We didn't get anywhere near actually using this lockres. */
        if (!(lockres->l_flags & OCFS2_LOCK_INITIALIZED))
                goto out;
 
+       if (lockres->l_ops->flags & LOCK_TYPE_USES_LVB)
+               lkm_flags |= LKM_VALBLK;
+
        spin_lock_irqsave(&lockres->l_lock, flags);
 
        mlog_bug_on_msg(!(lockres->l_flags & OCFS2_LOCK_FREEING),
@@ -2307,8 +2283,12 @@ static int ocfs2_drop_lock(struct ocfs2_super *osb,
                spin_lock_irqsave(&lockres->l_lock, flags);
        }
 
-       if (dcb)
-               dcb->drop_func(lockres, dcb->drop_data);
+       if (lockres->l_ops->flags & LOCK_TYPE_USES_LVB) {
+               if (lockres->l_flags & OCFS2_LOCK_ATTACHED &&
+                   lockres->l_level == LKM_EXMODE &&
+                   !(lockres->l_flags & OCFS2_LOCK_NEEDS_REFRESH))
+                       lockres->l_ops->set_lvb(lockres);
+       }
 
        if (lockres->l_flags & OCFS2_LOCK_BUSY)
                mlog(ML_ERROR, "destroying busy lock: \"%s\"\n",
@@ -2334,7 +2314,7 @@ static int ocfs2_drop_lock(struct ocfs2_super *osb,
 
        mlog(0, "lock %s\n", lockres->l_name);
 
-       status = dlmunlock(osb->dlm, &lockres->l_lksb, LKM_VALBLK,
+       status = dlmunlock(osb->dlm, &lockres->l_lksb, lkm_flags,
                           ocfs2_unlock_ast, lockres);
        if (status != DLM_NORMAL) {
                ocfs2_log_dlm_error("dlmunlock", status, lockres);
@@ -2388,7 +2368,7 @@ void ocfs2_simple_drop_lockres(struct ocfs2_super *osb,
        int ret;
 
        ocfs2_mark_lockres_freeing(lockres);
-       ret = ocfs2_drop_lock(osb, lockres, NULL);
+       ret = ocfs2_drop_lock(osb, lockres);
        if (ret)
                mlog_errno(ret);
 }
@@ -2399,22 +2379,9 @@ static void ocfs2_drop_osb_locks(struct ocfs2_super *osb)
        ocfs2_simple_drop_lockres(osb, &osb->osb_rename_lockres);
 }
 
-static void ocfs2_meta_pre_drop(struct ocfs2_lock_res *lockres, void *data)
-{
-       struct inode *inode = data;
-
-       /* the metadata lock requires a bit more work as we have an
-        * LVB to worry about. */
-       if (lockres->l_flags & OCFS2_LOCK_ATTACHED &&
-           lockres->l_level == LKM_EXMODE &&
-           !(lockres->l_flags & OCFS2_LOCK_NEEDS_REFRESH))
-               __ocfs2_stuff_meta_lvb(inode);
-}
-
 int ocfs2_drop_inode_locks(struct inode *inode)
 {
        int status, err;
-       struct drop_lock_cb meta_dcb = { ocfs2_meta_pre_drop, inode, };
 
        mlog_entry_void();
 
@@ -2422,24 +2389,21 @@ int ocfs2_drop_inode_locks(struct inode *inode)
         * ocfs2_clear_inode has done it for us. */
 
        err = ocfs2_drop_lock(OCFS2_SB(inode->i_sb),
-                             &OCFS2_I(inode)->ip_data_lockres,
-                             NULL);
+                             &OCFS2_I(inode)->ip_data_lockres);
        if (err < 0)
                mlog_errno(err);
 
        status = err;
 
        err = ocfs2_drop_lock(OCFS2_SB(inode->i_sb),
-                             &OCFS2_I(inode)->ip_meta_lockres,
-                             &meta_dcb);
+                             &OCFS2_I(inode)->ip_meta_lockres);
        if (err < 0)
                mlog_errno(err);
        if (err < 0 && !status)
                status = err;
 
        err = ocfs2_drop_lock(OCFS2_SB(inode->i_sb),
-                             &OCFS2_I(inode)->ip_rw_lockres,
-                             NULL);
+                             &OCFS2_I(inode)->ip_rw_lockres);
        if (err < 0)
                mlog_errno(err);
        if (err < 0 && !status)
@@ -2491,7 +2455,7 @@ static int ocfs2_downconvert_lock(struct ocfs2_super *osb,
                         OCFS2_LOCK_ID_MAX_LEN - 1,
                         ocfs2_locking_ast,
                         lockres,
-                        lockres->l_ops->bast);
+                        ocfs2_blocking_ast);
        if (status != DLM_NORMAL) {
                ocfs2_log_dlm_error("dlmlock", status, lockres);
                ret = -EINVAL;
@@ -2564,115 +2528,15 @@ static int ocfs2_cancel_convert(struct ocfs2_super *osb,
        return ret;
 }
 
-static inline int ocfs2_can_downconvert_meta_lock(struct inode *inode,
-                                                 struct ocfs2_lock_res *lockres,
-                                                 int new_level)
-{
-       int ret;
-
-       mlog_entry_void();
-
-       BUG_ON(new_level != LKM_NLMODE && new_level != LKM_PRMODE);
-
-       if (lockres->l_flags & OCFS2_LOCK_REFRESHING) {
-               ret = 0;
-               mlog(0, "lockres %s currently being refreshed -- backing "
-                    "off!\n", lockres->l_name);
-       } else if (new_level == LKM_PRMODE)
-               ret = !lockres->l_ex_holders &&
-                       ocfs2_inode_fully_checkpointed(inode);
-       else /* Must be NLMODE we're converting to. */
-               ret = !lockres->l_ro_holders && !lockres->l_ex_holders &&
-                       ocfs2_inode_fully_checkpointed(inode);
-
-       mlog_exit(ret);
-       return ret;
-}
-
-static int ocfs2_do_unblock_meta(struct inode *inode,
-                                int *requeue)
-{
-       int new_level;
-       int set_lvb = 0;
-       int ret = 0;
-       struct ocfs2_lock_res *lockres = &OCFS2_I(inode)->ip_meta_lockres;
-       unsigned long flags;
-
-       struct ocfs2_super *osb = OCFS2_SB(inode->i_sb);
-
-       mlog_entry_void();
-
-       spin_lock_irqsave(&lockres->l_lock, flags);
-
-       BUG_ON(!(lockres->l_flags & OCFS2_LOCK_BLOCKED));
-
-       mlog(0, "l_level=%d, l_blocking=%d\n", lockres->l_level,
-            lockres->l_blocking);
-
-       BUG_ON(lockres->l_level != LKM_EXMODE &&
-              lockres->l_level != LKM_PRMODE);
-
-       if (lockres->l_flags & OCFS2_LOCK_BUSY) {
-               *requeue = 1;
-               ret = ocfs2_prepare_cancel_convert(osb, lockres);
-               spin_unlock_irqrestore(&lockres->l_lock, flags);
-               if (ret) {
-                       ret = ocfs2_cancel_convert(osb, lockres);
-                       if (ret < 0)
-                               mlog_errno(ret);
-               }
-               goto leave;
-       }
-
-       new_level = ocfs2_highest_compat_lock_level(lockres->l_blocking);
-
-       mlog(0, "l_level=%d, l_blocking=%d, new_level=%d\n",
-            lockres->l_level, lockres->l_blocking, new_level);
-
-       if (ocfs2_can_downconvert_meta_lock(inode, lockres, new_level)) {
-               if (lockres->l_level == LKM_EXMODE)
-                       set_lvb = 1;
-
-               /* If the lock hasn't been refreshed yet (rare), then
-                * our memory inode values are old and we skip
-                * stuffing the lvb. There's no need to actually clear
-                * out the lvb here as it's value is still valid. */
-               if (!(lockres->l_flags & OCFS2_LOCK_NEEDS_REFRESH)) {
-                       if (set_lvb)
-                               __ocfs2_stuff_meta_lvb(inode);
-               } else
-                       mlog(0, "lockres %s: downconverting stale lock!\n",
-                            lockres->l_name);
-
-               mlog(0, "calling ocfs2_downconvert_lock with l_level=%d, "
-                    "l_blocking=%d, new_level=%d\n",
-                    lockres->l_level, lockres->l_blocking, new_level);
-
-               ocfs2_prepare_downconvert(lockres, new_level);
-               spin_unlock_irqrestore(&lockres->l_lock, flags);
-               ret = ocfs2_downconvert_lock(osb, lockres, new_level, set_lvb);
-               goto leave;
-       }
-       if (!ocfs2_inode_fully_checkpointed(inode))
-               ocfs2_start_checkpoint(osb);
-
-       *requeue = 1;
-       spin_unlock_irqrestore(&lockres->l_lock, flags);
-       ret = 0;
-leave:
-       mlog_exit(ret);
-       return ret;
-}
-
-static int ocfs2_generic_unblock_lock(struct ocfs2_super *osb,
-                                     struct ocfs2_lock_res *lockres,
-                                     struct ocfs2_unblock_ctl *ctl,
-                                     ocfs2_convert_worker_t *worker)
+static int ocfs2_unblock_lock(struct ocfs2_super *osb,
+                             struct ocfs2_lock_res *lockres,
+                             struct ocfs2_unblock_ctl *ctl)
 {
        unsigned long flags;
        int blocking;
        int new_level;
        int ret = 0;
+       int set_lvb = 0;
 
        mlog_entry_void();
 
@@ -2696,27 +2560,33 @@ recheck:
        /* if we're blocking an exclusive and we have *any* holders,
         * then requeue. */
        if ((lockres->l_blocking == LKM_EXMODE)
-           && (lockres->l_ex_holders || lockres->l_ro_holders)) {
-               spin_unlock_irqrestore(&lockres->l_lock, flags);
-               ctl->requeue = 1;
-               ret = 0;
-               goto leave;
-       }
+           && (lockres->l_ex_holders || lockres->l_ro_holders))
+               goto leave_requeue;
 
        /* If it's a PR we're blocking, then only
         * requeue if we've got any EX holders */
        if (lockres->l_blocking == LKM_PRMODE &&
-           lockres->l_ex_holders) {
-               spin_unlock_irqrestore(&lockres->l_lock, flags);
-               ctl->requeue = 1;
-               ret = 0;
-               goto leave;
-       }
+           lockres->l_ex_holders)
+               goto leave_requeue;
+
+       /*
+        * Can we get a lock in this state if the holder counts are
+        * zero? The meta data unblock code used to check this.
+        */
+       if ((lockres->l_ops->flags & LOCK_TYPE_REQUIRES_REFRESH)
+           && (lockres->l_flags & OCFS2_LOCK_REFRESHING))
+               goto leave_requeue;
+
+       new_level = ocfs2_highest_compat_lock_level(lockres->l_blocking);
+
+       if (lockres->l_ops->check_downconvert
+           && !lockres->l_ops->check_downconvert(lockres, new_level))
+               goto leave_requeue;
 
        /* If we get here, then we know that there are no more
         * incompatible holders (and anyone asking for an incompatible
         * lock is blocked). We can now downconvert the lock */
-       if (!worker)
+       if (!lockres->l_ops->downconvert_worker)
                goto downconvert;
 
        /* Some lockres types want to do a bit of work before
@@ -2726,7 +2596,7 @@ recheck:
        blocking = lockres->l_blocking;
        spin_unlock_irqrestore(&lockres->l_lock, flags);
 
-       ctl->unblock_action = worker(lockres, blocking);
+       ctl->unblock_action = lockres->l_ops->downconvert_worker(lockres, blocking);
 
        if (ctl->unblock_action == UNBLOCK_STOP_POST)
                goto leave;
@@ -2740,14 +2610,34 @@ recheck:
 
 downconvert:
        ctl->requeue = 0;
-       new_level = ocfs2_highest_compat_lock_level(lockres->l_blocking);
+
+       if (lockres->l_ops->flags & LOCK_TYPE_USES_LVB) {
+               if (lockres->l_level == LKM_EXMODE)
+                       set_lvb = 1;
+
+               /*
+                * We only set the lvb if the lock has been fully
+                * refreshed - otherwise we risk setting stale
+                * data. Otherwise, there's no need to actually clear
+                * out the lvb here as it's value is still valid.
+                */
+               if (set_lvb && !(lockres->l_flags & OCFS2_LOCK_NEEDS_REFRESH))
+                       lockres->l_ops->set_lvb(lockres);
+       }
 
        ocfs2_prepare_downconvert(lockres, new_level);
        spin_unlock_irqrestore(&lockres->l_lock, flags);
-       ret = ocfs2_downconvert_lock(osb, lockres, new_level, 0);
+       ret = ocfs2_downconvert_lock(osb, lockres, new_level, set_lvb);
 leave:
        mlog_exit(ret);
        return ret;
+
+leave_requeue:
+       spin_unlock_irqrestore(&lockres->l_lock, flags);
+       ctl->requeue = 1;
+
+       mlog_exit(0);
+       return 0;
 }
 
 static int ocfs2_data_convert_worker(struct ocfs2_lock_res *lockres,
@@ -2779,76 +2669,27 @@ static int ocfs2_data_convert_worker(struct ocfs2_lock_res *lockres,
        return UNBLOCK_CONTINUE;
 }
 
-int ocfs2_unblock_data(struct ocfs2_lock_res *lockres,
-                      struct ocfs2_unblock_ctl *ctl)
+static int ocfs2_check_meta_downconvert(struct ocfs2_lock_res *lockres,
+                                       int new_level)
 {
-       int status;
-       struct inode *inode;
-       struct ocfs2_super *osb;
+       struct inode *inode = ocfs2_lock_res_inode(lockres);
+       int checkpointed = ocfs2_inode_fully_checkpointed(inode);
 
-       mlog_entry_void();
-
-       inode = ocfs2_lock_res_inode(lockres);
-       osb = OCFS2_SB(inode->i_sb);
-
-       mlog(0, "unblock inode %llu\n",
-            (unsigned long long)OCFS2_I(inode)->ip_blkno);
-
-       status = ocfs2_generic_unblock_lock(osb, lockres, ctl,
-                                           ocfs2_data_convert_worker);
-       if (status < 0)
-               mlog_errno(status);
+       BUG_ON(new_level != LKM_NLMODE && new_level != LKM_PRMODE);
+       BUG_ON(lockres->l_level != LKM_EXMODE && !checkpointed);
 
-       mlog(0, "inode %llu, requeue = %d\n",
-            (unsigned long long)OCFS2_I(inode)->ip_blkno, ctl->requeue);
+       if (checkpointed)
+               return 1;
 
-       mlog_exit(status);
-       return status;
+       ocfs2_start_checkpoint(OCFS2_SB(inode->i_sb));
+       return 0;
 }
 
-static int ocfs2_unblock_inode_lock(struct ocfs2_lock_res *lockres,
-                                   struct ocfs2_unblock_ctl *ctl)
+static void ocfs2_set_meta_lvb(struct ocfs2_lock_res *lockres)
 {
-       int status;
-       struct inode *inode;
-
-       mlog_entry_void();
-
-       mlog(0, "Unblock lockres %s\n", lockres->l_name);
-
-       inode  = ocfs2_lock_res_inode(lockres);
+       struct inode *inode = ocfs2_lock_res_inode(lockres);
 
-       status = ocfs2_generic_unblock_lock(OCFS2_SB(inode->i_sb),
-                                           lockres, ctl, NULL);
-       if (status < 0)
-               mlog_errno(status);
-
-       mlog_exit(status);
-       return status;
-}
-
-static int ocfs2_unblock_meta(struct ocfs2_lock_res *lockres,
-                             struct ocfs2_unblock_ctl *ctl)
-{
-       int status;
-       struct inode *inode;
-
-       mlog_entry_void();
-
-               inode = ocfs2_lock_res_inode(lockres);
-
-       mlog(0, "unblock inode %llu\n",
-            (unsigned long long)OCFS2_I(inode)->ip_blkno);
-
-       status = ocfs2_do_unblock_meta(inode, &ctl->requeue);
-       if (status < 0)
-               mlog_errno(status);
-
-       mlog(0, "inode %llu, requeue = %d\n",
-            (unsigned long long)OCFS2_I(inode)->ip_blkno, ctl->requeue);
-
-       mlog_exit(status);
-       return status;
+       __ocfs2_stuff_meta_lvb(inode);
 }
 
 /*
@@ -2973,53 +2814,6 @@ static int ocfs2_dentry_convert_worker(struct ocfs2_lock_res *lockres,
        return UNBLOCK_CONTINUE_POST;
 }
 
-static int ocfs2_unblock_dentry_lock(struct ocfs2_lock_res *lockres,
-                                    struct ocfs2_unblock_ctl *ctl)
-{
-       int ret;
-       struct ocfs2_dentry_lock *dl = ocfs2_lock_res_dl(lockres);
-       struct ocfs2_super *osb = OCFS2_SB(dl->dl_inode->i_sb);
-
-       mlog(0, "unblock dentry lock: %llu\n",
-            (unsigned long long)OCFS2_I(dl->dl_inode)->ip_blkno);
-
-       ret = ocfs2_generic_unblock_lock(osb,
-                                        lockres,
-                                        ctl,
-                                        ocfs2_dentry_convert_worker);
-       if (ret < 0)
-               mlog_errno(ret);
-
-       mlog(0, "requeue = %d, post = %d\n", ctl->requeue, ctl->unblock_action);
-
-       return ret;
-}
-
-/* Generic unblock function for any lockres whose private data is an
- * ocfs2_super pointer. */
-static int ocfs2_unblock_osb_lock(struct ocfs2_lock_res *lockres,
-                                 struct ocfs2_unblock_ctl *ctl)
-{
-       int status;
-       struct ocfs2_super *osb;
-
-       mlog_entry_void();
-
-       mlog(0, "Unblock lockres %s\n", lockres->l_name);
-
-       osb = ocfs2_lock_res_super(lockres);
-
-       status = ocfs2_generic_unblock_lock(osb,
-                                           lockres,
-                                           ctl,
-                                           NULL);
-       if (status < 0)
-               mlog_errno(status);
-
-       mlog_exit(status);
-       return status;
-}
-
 void ocfs2_process_blocked_lock(struct ocfs2_super *osb,
                                struct ocfs2_lock_res *lockres)
 {
@@ -3035,7 +2829,6 @@ void ocfs2_process_blocked_lock(struct ocfs2_super *osb,
 
        BUG_ON(!lockres);
        BUG_ON(!lockres->l_ops);
-       BUG_ON(!lockres->l_ops->unblock);
 
        mlog(0, "lockres %s blocked.\n", lockres->l_name);
 
@@ -3049,7 +2842,7 @@ void ocfs2_process_blocked_lock(struct ocfs2_super *osb,
                goto unqueue;
        spin_unlock_irqrestore(&lockres->l_lock, flags);
 
-       status = lockres->l_ops->unblock(lockres, &ctl);
+       status = ocfs2_unblock_lock(osb, lockres, &ctl);
        if (status < 0)
                mlog_errno(status);